Vacancies in as-grown CZ silicon crystals observed by low-temperature ultrasonic measurements

Hiroshi Yamada-Kaneta, Terutaka Goto, Yuichi Nemoto, Koji Sato, Masatoshi Hikin, Yasuhiro Saito, Shintaro Nakamura

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3 Citations (Scopus)


By means of the low-temperature ultrasonic measurement, we try to observe the elastic softening due to the vacancies in as-grown silicon crystals grown by the Czochralski (CZ) method. We prepared a high-resistivity CZ silicon crystal ingot comprising the following defect-regions: the void region, the region of ring-like oxidation stacking fault, the Pv-region, the Pi-region, and the region of the dislocation clusters. Both of the elastic constants C 44(T) and [C 11(T)-C 12(T)]/2 measured for the samples taken from the Pv-region exhibit the softening of the type C Γ(T) = C Γ (0) [1- JT/(T - Θ)] which was also found in our previous study for the non-doped FZ silicon and attributed to the neutral vacancy. No response of the softening to the applied magnetic field is found, as in our previous case of the non-doped FZ silicon. The observed softenings are attributed to the triply degenerate T 2 states of the vacancy accommodating two electrons with anti parallel spins. The samples in the Pi-region exhibit no such softening, confirming that the origin of the softening is the vacancies. A qualitative explanation is given to the measured distribution of the vacancy concentration.

Original languageEnglish
Pages (from-to)S19-S23
JournalJournal of Materials Science: Materials in Electronics
Issue numberSUPPL. 1
Publication statusPublished - 2008

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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